相关论文: K I 7699 {\AA} and related shell lines during the …
The results of a spectroscopic survey of epsilon Aurigae during eclipse using a network of small telescopes are presented. The spectra have a resolution of 0.35 to 0.65{\AA} and cover the period 2008 to 2012 with a typical interval of 4…
The discovery of K I 7699{\AA} line strength variations during the 1982-1984 eclipse of {\epsilon} Aurigae is described. The equivalent widths and radial velocities of the K I 7699{\AA} line derived from spectra obtained during 1981…
Spatially-resolved high-resolution long-slit spectra of Betelgeuse's circumstellar shell are described for a spectral window centered on the 7699\AA resonance line of neutral potassium. The K I emission from resonance fluorescent scattering…
We report new and archival K-band interferometric uniform disk diameters obtained with the Palomar Testbed Interferometer for the eclipsing binary star $\epsilon$ Aurigae, in advance of the start of its eclipse in 2009. The observations…
A series of 353 red electronic spectra obtained between 1994 and 2010, and of 171 UBV photometric observations of the 2010 eclipse, were analyzed in an effort to better understand the eclipsing binary eps Aur. The main results follow. (1)…
The results of the spectral observations of a unique eclipsing system {\epsilon} Aurigae obtained during the recent eclipse are presented. We traced the spectral lines variations at different eclipse phases. The part of these changes is the…
Variations in the equivalent width of the neutral potassium line at 7699A are reported, during ingress and into totality of the current eclipse of the enigmatic eclipsing binary epsilon Aurigae. The increase and plateaus of line strength…
We report on a total of 106 nights of optical interferometric observations of the $\epsilon$ Aurigae system taken during the last 14 years by four beam combiners at three different interferometric facilities. This long sequence of data…
We present both binarity and pulsation of KIC 6220497 from the {\it Kepler} observations. The light curve synthesis shows that the eclipsing system is a semi-detached Algol with parameters of $q$ = 0.243$\pm$0.001, $i$ = 77.3$\pm$0.3 deg,…
We present high spectral-resolution optical spectra of 49 Herbig Ae/Be stars in a search for the [O I] 6300A line. The vast majority of the stars in our sample show narrow (FWHM < 100 km/s) emission lines, centered on the stellar radial…
A rare eclipse of the mysterious object Epsilon Aurigae will occur in 2009-2011. We report an updated single-lined spectroscopic solution for the orbit of the primary star based on 20 years of monitoring at the CfA, combined with historical…
V454 Aur is an eclipsing binary system containing two solar-type stars on an orbit of relatively long period (P = 27.02 d) and large eccentricity (e = 0.381). Eclipses were detected using data from the Hipparcos satellite, and a…
We present the physical properties of KIC 5621294 showing light and timing variations from the ${\it Kepler}$ photometry. Its light curve displays partial eclipses and O'Connell effect with Max II fainter than Max I, which was fitted quite…
T Aurigae is an eclipsing old nova which exploded in 1891. At a Gaia EDR3 distance of 815-871 pc, it is a relatively nearby old nova. Through ultraviolet spectral modeling and using the new precise Gaia distance, we find that the HST/STIS…
Context: Worldwide interest in the recent eclipse of epsilon Aurigae resulted in the generation of several extensive data sets, including those related to high resolution spectroscopic monitoring. This lead to the discovery, among other…
We present and analyze epsilon Aurigae data concerning the evolution of the H$\alpha$ line on the occasion of the 2009 International observation campaign launched to cover the eclipse of this object. About 250 high resolution spectra of the…
A detailed analysis of the radiative and Auger de-excitation channels of K-shell vacancy states in Fe II-Fe IX has been carried out. Level energies, wavelengths, A-values, Auger rates and fluorescence yields have been calculated for the…
We present a second paper related to the analyses of high-dispersion spectroscopic observations of the magnetic cataclysmic variable AE Aquarii. We focus our efforts on the study of the emission lines and their radial velocities. We detect…
The spectrum of the normal Type Ia SN 1990N observed very early on (14 days before B maximum) was analysed by Fisher et al (1997), who showed that the large width and the unusual profile of the strong line near 6000\AA can be reproduced if…
A study on the intermediate polar EX Hya is presented, based on simultaneous photometry and high dispersion spectroscopic observations, during four consecutive nights. The strong photometric modulation related to with the 67-min spin period…